Improvement in steam-boilers



UNITED STATES PATENT OFFICE...

IMPROVEMENT IN STEAM-BOILERS.

Specification forming part of Letters Patent No. 34,823, dated April 1,1862.

' To all whom it may concern:

Beit known that I, JOSEPH P. EVANS, of Hazleton, in the county ofLuzerne and State of Pennsylvania, have invented certain new and usefulImprovements in Furnaces for Steam-Boilers; and I do hereby declare thatthe following is a full, clear, and exact description of the same,reference being had to the accompanying drawings, forming part of thisspecification, in which- Figure l is a longitudinal vertical section ofa locomotive iire-box with my invention applied. Fig. 2 is a transversevertical sec tion of the same. Fig. 3 is a plan of the interior of thesame. Fig. 4 is a transverse section of one of the elliptical bars.

Similar letters of reference indicate corresponding parts in the severaligures.

This invention consists in the combination for the grate of aboilerfurnace of a series of tubular bars of elliptical or substantiallysimilar form in their transverse section and a series ofalternately-interposed tubular or solid bars of round form, theelliptical bars being so much deeper than the round ones as to expose agreat portion of their surface to lateral contact with the incandescentfuel upon the grate and cause the rapid generation of steam from thewater,which circulates through them between the water-spaces at oppositeends of the fire-box.

It also consists in the arrangement within and at the sides and ends ofthe fire-box of bent pipes having an elliptical or attened transversesection connected each at one end with the upper part of the water-spacesurrounding the lire-box and at the other end with a lower portion ofsaid water-space, such pipes being exposed to the intense radiant heatof the fire and to the contact of the heated and iniiamed gases ofcombustion, and having induced through them a material circulation ofwater which is rapidly converted into steam.

To enable others skilled in the art to make and use my invention, lwillproceed to describe its construction and operation.

A is the fire-box.

B B are the elliptical tubular grate-bars, and C C the interposed roundbars, also repre= sented of tubularconstruction, all of said barscommunicating with the water-spaces at the front and back of thelire-box.

The elliptical bars B B are set up edgewise-that is to say, with theirgreater diameter in a vertical direction, and this diameter is so muchgreater than that of the interposed round bars C O that, though all arearranged with their bottoms about on the same level, the said bars B Bstand high above C C, with the greater, or avery considerable, portionof their surfaces in contact with the fuel, which enters the spacesbetween them and above C C, and by the use of this system of ellipticaland interposed round bars a greater area of surface is exposed inlateral contact with the re than is done by the zigzag arrangement ofround bars lately introduced.

D D are the bent pipes arranged at the sides and ends of the fire-box.These pipes are straight for the greater portion of their length, buthave elbows at top and bottom to enable them to be connected with thewaterspace surrounding the fire-box. Their transverse section is ofelliptical or flattened form, and they are arranged with the portionbetween the elbows either upright or inclined in such a way as to keepthe lower parts nearer than the upper parts to the sides and ends of thefire-box. The said pipes, being exposed to the radiant heat of theincandescent fuel on the grate and to the contact of the iiame andheated gases evolved from the fuel, are subjected to a very great heat,and the water in them is rapidly converted into steam; but at the sametime so rapid an upward circulation of water is induced within them asto prevent them from being overheated.

E E are horizontal pipes arranged parallel with the sides of thelire-box and connecting the pipes D with each other and with thewater-space at the ends of the fire-box. These pipes also serve asheating-surfaces, in contact with which a rapid generation of steamtakes place, and at the same time they aid the circulation in D D.Similar pipes to E E may be employed to connect the pipes D D at theends of the fire-box with each other and with the water-spaces at thesides of the tire-box.

I do not claim, broadly, the invention of tubular ire-grates, nor do Iclailn the use of 2. The arrangement of the elliptical pipes Water-tubesWi thin the fire-box connecting the D and connecting-pipes E With eachother and upper and lower parts of the boiler; but with the boiler A, asherein shown and de- What I claiin as my invention, and desire seribed.to secure Aby Letters Patent, is

l. Having the re-grate made with an alternate arrangement of largeelliptical tubes and small cylindrical tubes or bars, in the mannerWitnesses: and for the purpose herein shown and de- THOMAS EVANS,

JOSEPH P. EVANS.

scribed. WILLIAM GETTRING.

